1. Field of the Invention
This invention relates to an improved approach to the casting of metal ingot molds and particularly, to an improved method and assembly which minimize the quantity requirements for casting sand. A phase of the invention deals with an approach to casting ingot molds which will provide an effectively combined usage of an inwardly positioned refractory lining and refractory coat with quick-set cheek casting sand.
2. Description of the Prior Art
It has heretofore been customary in the forming of cast hollow ingot molds to make use of ordinary silica casting sand for both protecting the metal parts and providing a mold cavity and which after the shaping of the mold cavity, requires a fuel-applied baking period of about 24 hours. Although Quaker Oats Company, as well as Ashland Oil have made available a so-called quick or air set synthetic sand for casting which saves energy from the standpoint of drying fuel and may be set within a short drying period of about 30 minutes, its usage has not been entirely satisfactory employing the type of mold assemblies that have heretofore been available. The expense has been somewhat prohibitive in view of the conventional, one-use, quantity required for the casting of ingot molds due to their relative large sizes.
In today's environment there is a definite need to not only conserve fuel and other forms of energy, but to avoid pollution and, in this connection, to minimize the quantity of core sand that must be discarded. Using present practice, the flask is faced with a heavy thickness of cheek sand and the of core bar with a heavy thickness core sand, with the molten iron being poured within the mold cavity between them to form the casting. A relatively large volume of sand is required for the operation. Even when ordinary sand is used, a large percentage of the sand must be discarded and replaced. In most cases the complete volume must be discarded.
Although this sand problem has heretofore been minor, it is now an important factor from the standpoint of finding a suitable dumping spot and also from the standpoint of the higher present day cost of even ordinary sand. Thus, there is a need for decreasing the quantity of sand required in the casting operation. As will be appreciated, the quantity may be very large using the conventional approach, since ingot mold castings usually run in the size range of 500 to 50,000 lbs.
There is a need for protecting as well as for minimizing wear and tear on the metal casting flask and core bar, in addition to minimizing the amount of sand that has to be discarded, and in making practical the full employment of so-called quick-set, air drying resin-containing casting sand.